/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2000 Intersect Software Corporation

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.ui.swing;

import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Enumeration;

import net.wotonomy.foundation.NSArray;
import net.wotonomy.foundation.NSSelector;
import net.wotonomy.foundation.internal.ValueConverter;
import net.wotonomy.foundation.internal.WotonomyException;
import net.wotonomy.ui.EOAssociation;
import net.wotonomy.ui.EODisplayGroup;

/**
 * ActionAssociation binds any ActionEvent broadcaster (typically Buttons and
 * the like) to a display group. Actions are invoked on all selected objects in
 * the display group bound to the action aspect. Bindings are:
 * <ul>
 * <li>action: a method to be invoked on selected objects. If the argument
 * aspect is bound, the method must take one argument. Otherwise, the method
 * must take no arguments.</li>
 * <li>argument: the attribute of the selected object(s) (possibly from a
 * different display group) that will be used as an argument to the action
 * method</li>
 * <li>enabled: a boolean property that determines whether the controlled
 * component is enabled</li>
 * <li>visible: a boolean property that determines whether the controlled
 * component is visible</li>
 * </ul>
 *
 * @author michael@mpowers.net
 * @author $Author: cgruber $
 * @version $Revision: 904 $
 */
public class ActionAssociation extends EOAssociation implements ActionListener {
	static final NSArray aspects = new NSArray(
			new Object[] { ActionAspect, ArgumentAspect, EnabledAspect, VisibleAspect });
	static final NSArray aspectSignatures = new NSArray(new Object[] { AttributeToOneAspectSignature,
			AttributeToOneAspectSignature, AttributeToOneAspectSignature, AttributeToOneAspectSignature });
	static final NSArray objectKeysTaken = new NSArray(new Object[] { "target" });

	static NSSelector addActionListener = new NSSelector("addActionListener", new Class[] { ActionListener.class });
	static NSSelector removeActionListener = new NSSelector("removeActionListener",
			new Class[] { ActionListener.class });

	/**
	 * Constructor specifying the object to be controlled by this association. Does
	 * not establish connection.
	 */
	public ActionAssociation(Object anObject) {
		super(anObject);
	}

	/**
	 * Returns a List of aspect signatures whose contents correspond with the
	 * aspects list. Each element is a string whose characters represent a
	 * capability of the corresponding aspect.
	 * <ul>
	 * <li>"A" attribute: the aspect can be bound to an attribute.</li>
	 * <li>"1" to-one: the aspect can be bound to a property that returns a single
	 * object.</li>
	 * <li>"M" to-one: the aspect can be bound to a property that returns multiple
	 * objects.</li>
	 * </ul>
	 * An empty signature "" means that the aspect can bind without needing a key.
	 * This implementation returns "A1M" for each element in the aspects array.
	 */
	public static NSArray aspectSignatures() {
		return aspectSignatures;
	}

	/**
	 * Returns a List that describes the aspects supported by this class. Each
	 * element in the list is the string name of the aspect. This implementation
	 * returns an empty list.
	 */
	public static NSArray aspects() {
		return aspects;
	}

	/**
	 * Returns a List of EOAssociation subclasses that, for the objects that are
	 * usable for this association, are less suitable than this association.
	 */
	public static NSArray associationClassesSuperseded() {
		return new NSArray();
	}

	/**
	 * Returns whether this class can control the specified object.
	 */
	public static boolean isUsableWithObject(Object anObject) {
		return (addActionListener.implementedByObject(anObject))
				&& (removeActionListener.implementedByObject(anObject));
	}

	/**
	 * Returns a List of properties of the controlled object that are controlled by
	 * this class. For example, "stringValue", or "selected".
	 */
	public static NSArray objectKeysTaken() {
		return objectKeysTaken;
	}

	/**
	 * Returns the aspect that is considered primary or default.
	 */
	public static String primaryAspect() {
		return ActionAspect;
	}

	/**
	 * Returns whether this association can bind to the specified display group on
	 * the specified key for the specified aspect.
	 */
	public boolean canBindAspect(String anAspect, EODisplayGroup aDisplayGroup, String aKey) {
		return (aspects.containsObject(anAspect));
	}

	/**
	 * Establishes a connection between this association and the controlled object.
	 * Subclasses should begin listening for events from their controlled object
	 * here.
	 */
	public void establishConnection() {
		try {
			addActionListener.invoke(object(), this);
		} catch (Exception exc) {
			throw new WotonomyException(
					"EOActionAssociation: " + "could not add action listener to object:" + object());
		}
		super.establishConnection();
	}

	/**
	 * Breaks the connection between this association and its object. Override to
	 * stop listening for events from the object.
	 */
	public void breakConnection() {
		try {
			removeActionListener.invoke(object(), this);
		} catch (Exception exc) {
			throw new WotonomyException(
					"EOActionAssociation: " + "could not add action listener to object:" + object());
		}
		super.breakConnection();
	}

	/**
	 * Called when either the selection or the contents of an associated display
	 * group have changed. This implementation does nothing.
	 */
	public void subjectChanged() {
		Object component = object();
		EODisplayGroup displayGroup;
		String key;

		if (component instanceof Component) {
			// enabled aspect
			displayGroup = displayGroupForAspect(EnabledAspect);
			if (displayGroup != null) {
				key = displayGroupKeyForAspect(EnabledAspect);
				((Component) component).setEnabled(displayGroup.enabledToSetSelectedObjectValueForKey(key));
				Object value = displayGroup.selectedObjectValueForKey(key);
				Boolean converted = null;
				if (value != null) {
					converted = (Boolean) ValueConverter.convertObjectToClass(value, Boolean.class);
				}
				if (converted == null)
					converted = Boolean.FALSE;
				if (converted.booleanValue() != ((Component) component).isEnabled()) {
					((Component) component).setEnabled(converted.booleanValue());
				}
			}

			// visible aspect
			displayGroup = displayGroupForAspect(VisibleAspect);
			if (displayGroup != null) {
				key = displayGroupKeyForAspect(VisibleAspect);
				Object value = displayGroup.selectedObjectValueForKey(key);
				Boolean converted = (Boolean) ValueConverter.convertObjectToClass(value, Boolean.class);
				if (converted != null) {
					if (converted.booleanValue() != ((Component) component).isVisible()) {
						((Component) component).setVisible(converted.booleanValue());
					}
				}
			}
		}
	}

	// interface ActionListener

	public void actionPerformed(ActionEvent evt) {
		EODisplayGroup actionDisplayGroup = null;
		String actionKey = null;

		// action aspect
		actionDisplayGroup = displayGroupForAspect(ActionAspect);
		if (actionDisplayGroup != null) {
			actionKey = displayGroupKeyForAspect(ActionAspect);

			// TODO: argument aspect not implemented

			try {

				NSSelector selector = new NSSelector(actionKey);
				Enumeration e = actionDisplayGroup.selectedObjects().objectEnumerator();
				while (e.hasMoreElements()) {
					selector.invoke(e.nextElement());
				}
			} catch (Exception exc) {
				throw new WotonomyException("ActionAssociation: error invoking action: " + actionKey, exc);
			}
		}
	}
}

/*
 * $Log$ Revision 1.2 2006/02/18 23:19:05 cgruber Update imports and maven
 * dependencies.
 *
 * Revision 1.1 2006/02/16 13:22:22 cgruber Check in all sources in
 * eclipse-friendly maven-enabled packages.
 *
 * Revision 1.4 2004/01/28 18:34:57 mpowers Better handling for enabling. Now
 * respecting enabledToSetSelectedObjectValueForKey from display group.
 *
 * Revision 1.3 2003/08/06 23:07:52 chochos general code cleanup (mostly,
 * removing unused imports)
 *
 * Revision 1.2 2001/02/17 16:52:05 mpowers Changes in imports to support
 * building with jdk1.1 collections.
 *
 * Revision 1.1.1.1 2000/12/21 15:48:28 mpowers Contributing wotonomy.
 *
 * Revision 1.5 2000/12/20 16:25:40 michael Added log to all files.
 *
 *
 */